Field of the Invention
Systems and methods for measuring an analyte in a host are provided. More particularly, systems and methods are provided for applying a transcutaneous analyte measurement system to a host.
Description of the Related Technology
Diabetes mellitus is a disorder in which the pancreas cannot create sufficient insulin (Type I or insulin dependent) and/or in which insulin is not effective (Type 2 or non-insulin dependent). In the diabetic state, the victim suffers from high blood sugar, which can cause an array of physiological derangements associated with the deterioration of small blood vessels, for example, kidney failure, skin ulcers, or bleeding into the vitreous of the eye. A hypoglycemic reaction (low blood sugar) can be induced by an inadvertent overdose of insulin, or after a normal dose of insulin or glucose-lowering agent accompanied by extraordinary exercise or insufficient food intake.
Conventionally, a person with diabetes carries a self-monitoring blood glucose (SMBG) monitor, which typically requires uncomfortable finger pricking methods. Due to the lack of comfort and convenience, a person with diabetes normally only measures his or her glucose levels two to four times per day. Unfortunately, such time intervals are spread so far apart that the person with diabetes likely finds out too late of a hyperglycemic or hypoglycemic condition, sometimes incurring dangerous side effects. Glucose levels may be alternatively monitored continuously by a sensor system including an on-skin sensor assembly. The sensor system may have a wireless transmitter which transmits measurement data to a receiver which can process and display information based on the measurements.
The process of applying the sensor to the person is important for such a system to be effective and user friendly. The application process should result in the sensor assembly being attached to the person in a state where it is capable of sensing glucose level information, communicating the sensed data to the transmitter, and transmitting the glucose level information to the receiver.
Exemplary prior art systems are disclosed in, e.g., US PGP 2014/0088389 and US PGP 2013/0267813, owned by the assignee of the present application and herein incorporated by reference in their entireties. Such systems tended to rely on particular configurations of a spring and a seal. These configurations resulted in certain disadvantages. For example, portions of the movement occurred when the spring was at its lowest force, e.g., at the end of its extension or compression, i.e., at its equilibrium position. In addition, as the spring was maintained in a compressed or extended or otherwise preloaded condition, between the time of manufacture and the time of activation, the same could undergo mechanical fatigue during this time. Such may in addition result in cause mechanical “creep”, particularly in plastic components.
Other issues include that certain elements, particularly seals, were subject to “slingshotting” as insertion elements underwent movements caused by the insertion routine such effects resulting in inaccurate sensor wire placement, as the amount of slingshotting is unpredictable. In addition, where a single spring was suggested in prior implementations, the same would generally have to be a large spring to accommodate all the motion required in insertion and retraction, and such a large spring may be expected to deleteriously cause tissue trauma as the needle and sensor were forcefully inserted into a host.
This Background is provided to introduce a brief context for the Summary and Detailed Description that follow. This Background is not intended to be an aid in determining the scope of the claimed subject matter nor be viewed as limiting the claimed subject matter to implementations that solve any or all of the disadvantages or problems presented above.